ALIMENTARY CANAL. 91 



The intestinal canal of the Congo Snake {Amphiuma means) resembles, in many 

 respects, that of Ophidians (see Fig. 20). 



The intestinal canal of carnivorous chelonians, as the Yellow-bellied Terrapin 

 {Emys serrata), Chicken Terrapin {Emys reticulata), Salt-water Terrapin {Etnys 

 terrapin), and Snapping Turtle [Chelonura serjjetitma) , is shorter and much less 

 capacious than that of the graminivorous Gopher [Testudo polypliemus) . 



A comparison of the viscera of a carnivorous chelonian, as the Snapping Turtle 

 [Chelonura serpentina) (Fig. 8), with the viscera of a graminivorous chelonian, as 

 the Gopher [Testudo polypliemus) (Fig. 9), shows the modifications by which the 

 alimentary canal is adapted to the habits and food of animals. 



Fic. 9. 



Viscera of the Gopher [Tesiudo polypliemus), a graminivorous chelonian, reJuced to one-half diameter. A, A. Muscles. 

 B, B. Auricles of heart. C. Ventricle of heart. F, F, F, F. Lungs; the lungs of this chelonian are very 

 extensive. D, D. Liver. G. Stomach. H. Inferior portion of the small intestine. I, K. The large intestine, 

 filled with grass and vegetable matters. M. Bladder: the bladder of the Gopher is capacious, and in medium- 

 sized individuals of this species, often contains five fluid ounces of urine ; the bladder empties its contents into 

 the lower portion of the large intestine, or cloaca. 0. Cloaca. R. Tail and anus: the tail is remarkably small 

 and short in the Testudo polyphemus. 



In all the gophers that I have examined, the stomach and small intestines were 

 completely empty ; while the colon and rectum, which are developed to an enor- 

 mous extent, were packed with grasses and leaves. The vegetable food contained 

 in the colon and rectum of medium-sized gophers, often amounted to several thou- 

 sand grains. 



These animals are able to do without food and drink much longer than car- 

 nivorous chelonians, because the wastes of the solids and fluids are supplied from 

 this capacious storehouse of nutritive materials. 



When carnivorous terrapins were starved for a length of time, and then fed upon 



